PURPOSE: To manufacture thermistors having different sizes and calorific values readily by forming a pair of comb-line electrodes on a main surface of a long size sheet body consisting of a material which is formed by diffusing conductive particles to an organic high polymer material and shows positive resistance temperature characteristics.

CONSTITUTION: Comb-line electrodes 23, 24 which consist of power sections 23a, 24a and conductive sections 23b, 24b are formed along a longer side section on one main surface of a long sheet 22 which is formed by fusing and extruding a positive characteristics thermistor material made by diffusing a conductive particle into an organic high polymer material. A thermistor sheet can be acquired by cutting off the sheet body 21.